1. Field of the Invention
The present invention relates to a combined broadcasting and communication system, and more particularly to a method of authenticating a channel authorization of a user during the combined service mode.
2. Description of the Related Art
FIG. 1 is a block diagram illustrating a general optical transmission network which provides a broadcasting service as well as a communication service. Referring to FIG. 1, a broadcasting service provider and a communication service provider transmit corresponding services to an OLT (Optical Line Terminal) 20. An optical cable is connected between the OLT 20 and an ONU (Optical Network Unit) 30 to exchange signals, such that when the corresponding service is provided from the ONU 30 to the user, the broadcasting service and the communication service can be transmitted separately. A set top box (STB) is commonly used for the transmission of the broadcasting service. The broadcasting service may be transmitted using an HFC (Hybrid Fiber Coaxial) cable network, a wireless network, or an optical cable such as FTTH.
When providing the broadcasting service, it is necessary to authenticate the user's authorization to access the broadcasting service and to perform the related accounting. To this end, an AAA (Authentication, Authorization and Accounting) server 10 is typically employed. The AAA server 10 provides authentication, authorization and accounting functions as the user tries to access computer resources.
FIGS. 2a and 2b are flowcharts illustrating the examples of a related art authentication process used in the broadcasting service.
Generally, in order to obtain an authorization for a channel desired by the user, private information is exchanged between the user's STB 40, the ONU 30 used for switching broadcasting stream to the user, and the AAA server 10. To receive a broadcasting service, the user activates the STB 40 to request a channel to the ONU 40, and in response, the ONU 30 requests the authorization to the AAA server 10, or the user's STB 40 requests the authorization to the AAA server 10 directly and then requests the desired channel to the ONU 30 using the authorization provided by the AAA server 10.
FIG. 2a is a flowchart illustrating the process in which the user (via STB 40) requests a channel to the ONU 30, and in turn, the ONU 30 requests the authorization to the AAA server 10 to perform the authentication. As shown, the STB 40 first requests a desired broadcasting service to the ONU 30 (step 201). Then, the ONU 30 requests the AAA server 10 whether the user has the authorization to access the corresponding service (step 202). At this time, the AAA server 10 performs the authentication, and transmits the result of authentication process to the ONU 30 as an authorization response (step 203). Thereafter, the ONU 30 provides the request service response according to the authentication result to the STB 40 (step 204).
FIG. 2b is a flowchart illustrating the process in which the user (e.g., STB 40) requests an authorization to the AAA server 10 directly and then requests a desired channel to the ONU 30 with the authentication approval. As shown, the STB 40 first requests whether it has the authorization to access the desired service by requesting an authorization to the AAA server 10. In response, the AAA server 10 performs the authentication, and transmits the authentication result to the STB 40 as an access response (step 206). Then, the STB 40 requests the broadcasting service according to the authorization result to the ONU 30 (step 207), and the ONU 30 provides the service to the STB 40 (step 208).
In order to obtain the broadcasting service from the ONU 30, the prior art requires to receive the authorization from the AAA server 10 or through the ONU 30. Accordingly, it takes longer for the STM 40 to request a channel and obtain the service using the prior art methods. Moreover, as the number of STBs 40 and services desired by the STBs 40 increase, the traffic between the ONU 30 and the AAA server 10 also increases to cause a more delay in obtaining the service. Furthermore, in the case that the AAA server 10 malfunctions or the ONU 30 and the AAA server 10 cannot communicate with each other, no service is provided to the STB 40.